Open-face clock



March 28, 1961 A. w. HAYDON OPEN-FACE CLOCK Filed Feb. 11, 1959 2 8 5 o 2 II n 2 z z .m s R y Y m m m G E G J W m H m l P I I I I I n O F m 5:5 f i w W n (J 5 t: E 1 S m. A 1 \II ii i i m 2 r Y B shaft and rotatable with respect thereto.

United States Patent OPEN -FACE CLOCK Arthur W. Haydon, Milford, Conn., assignor to The Sessions Clock Company, Forestville, Conm, a corporation of Connecticut Filed Feb. 11, 1959, Ser. No. 792,494

Claims. (Cl. 58-126) The present invention relates to clocks, and'more particularly to improvements in the construction thereof, whereby clocks of open-face design are rendered more practical and efficient. The term clock is not intended to be used ina restrictive sense herein, and refers to any device, for keeping time or for other uses, which incorporates a plurality of relatively moving hands or indicators.

One of the present trends of clock design is to provide so-called open-face clocks, in which the dial and hands are exposed. The open-face design is particularly popular in connection with wall clocks which, for example, may be of relatively large size and which are used, at least in large part, to provide a desirable artistic or decorative effect.

One of the substantial problems which arises in connection with the design of open-face clocks is that of preventing fouling of the moving parts by dust, grit, etc. Thus, the hands of a clock are driven by a mechanism which includes a shaft and one or more sleeves surrounding the The shaft and the sleeve or sleeves are driven by a clock motor, which may be electrically or otherwise powered, and the ends of the shaft and sleeves project through the clock face or dial and are exposed at that point. In normal clock design, no problem is thereby presented, since the entire front face of the clock is enclosed by a transparent cover. However, in an open-face clock, the moving parts are continually exposed to the atmosphere and will, over a period of time, pick up foreign material which becomes lodged between relatively moving surfaces and fouls the operation of the clock. The problem is particularly acute in connection with the so-called second hand of a clock, for example, since the shaft for operating the second hand rotates at relatively high speed and is driven through a system of low mechanical advantage, at least in comparison to the other hands of the clock.

In accordance with the present invention, a novel and improved open-face clock construction is provided which permits the lowest order indicator of a clock (usually the second hand) to be completely sealed from the atmosphere, while open-face design is otherwise retained. More specifically, the new clock includes enclosure means mounted on and carried by the drive means of the second lowest order, which would be the minute hand sleeve in a clock incorporating a second hand. The enclosure seals the open end of the sleeve and the lowest order drive member positioned therein, so that foreign matter is excluded from the most critical area of the clock.

For abetter understanding of the invention, reference should be made to the following detailed description and to the accompanying drawing, in which:

Fig. 1 is a fragmentary front view of a clock incorporating the features of the inventon;

Fig. 2 is an enlarged, fragmentary cross-sectional view taken generally along line 2-2 of Fig. 1;

Fig. 3 is an enlarged, fragmentary front view of a modification of the clock of Fig. 1;

Fig. '4 is a fragmentary, cross-sectional view taken generally on line 4-4 of Fig. 3; and

Fig. 5 is a front view of a further modified form of the new clock.

Referring initially to Figs. 1 and 2, the reference numeral 10 designates the dial or face of a clock of openface construction. The dial 10 has a central opening 11, through which project a plurality of coaxial drive members 12-14. The central drive member 12 may be a solid shaft and, in the illustrated device, is arranged to be driven by suitable means, such as a motor 10' at the rate of one revolution per minute. The intermediate and outer drive members 13, 14 are sleeves driven by the motor at the respective rates of one revolution per hour and one revolution per twelve hours.

In accordance with usual clock construction, the shaft 12 projects beyond the end of the sleeves 13, 14 and mounts a second hand or other indicator. Likewise, the intermediate sleeve 13 projects beyond the end of the outer sleeve 14 and mounts a minute hand 16. A portion of the outer sleeve 14 projects beyond the front face of the dial 10 and mounts an hour hand 17.

In a conventional clock of open-face design, with all of the drive members 12-14 exposed to the atomsphere, grit or other foreign matter may become lodged between the second hand shaft 12 and minute hand sleeve 13 or between the minute hand sleeve 13 and the hour hand sleeve 14. This may result in the clock being slowed down or stopped, and the problem is particularly acute in respect of the second hand shaft 12, which operates at the highest speed and with the lowest mechanical advantage.

In accordance with the invention, enclosure means 18 are provided for sealing off the exposed ends of the second hand shaft 12 and minute hand sleeve 13 to prevent the entry of any foreign matter between these members. Advantageously, the enclosure 18 comprises a disc-like back plate 19, which may be formed of metal or plastic, for example, and which is provided with a central opening 20 for receiving and frictionally gripping the end portion of the minute hand sleeve 13. In the illustrated device, the back plate 19 is provided with a peripheral lip 21 for engaging a transparent front cover or crystal 22.

As shown best in Fig. 2, the enclosure 18 is of suflicient diameter to accommodate the second hand 15 for unrestricted rotation. In this respect, it is contemplated that the second hand 15 will be of small radius in comparison to the minute and hour hands 16, 17, as indicated in Fig. 1.

In some cases, it is unnecessary or undesirable to provide a second hand, as such, but is desirable to provide an indicator, driven by the second hand shaft, from which it may be ascertained quickly whether the clock is operating properly. In such cases, it may be advantageous to utilize the modified arrangement of Figs. 3 and 4, in which the second hand shaft 12 mounts a disc 15 provided with areas of different color. The disc 15' may be of very small diameter, as no timing function is performed thereby and it is unnecessary to be able to read its position. Rather, it is sufficient if the disc 15 is sufficiently large so that its motion may be readily ascertained at a glance.

As shown in Fig. 4, the disc 15' is totally enclosed by a back plate 23 and crystal 24 carried by the minute hand sleeve 13'. The space between the shaft 12 and sleeve 13' is thus sealed oif, while open-face construction is otherwise observed.

Since the enclosure means of the invention is mounted on and rotates with the minute hand sleeve of the clock assembly, it may be desirable or expedient, in appropriate circumstances, to combine the enclosure means with the minute hand. Such an arrangement is shown in Fig. 5, wherein an enclosure unit 25, housing a second hand 26, is provided at one edge with an integral or attached pointer 27 which functions as a minute hand.

The invention is particularly advantageous in connection with battery operated wall clocks, for example, where it is particularly important to maintain friction losses at an absolute minimum. The new construction makes it possible to utilize open-face construction without substantial frictional losses in the operation of a second hand, and thus makes it-practical to employ a second hand or an indicator driven by a second hand shaft in a battery operated, open-face clock, for example.

It will be understood, of course, that the specific forms of the inventon herein illustrated and described are intended to be representative only ascertain changes may be made therein without departing from the clear teachings of the disclosure. Accordingly, reference should be made to the following appended claims in determining the full scope of the invention.

I claim:

1. An open-face clock assembly comprising a first rotatable member, a rotatable. sleeve surrounding the first rotatable member, drive means for rotating the member and sleeve at different speeds, a first indicator carried by the rotatable member, means forming a second indicator carried by the sleeve, and enclosure means carried by the sleeve and substantially totally enclosing the first indicator, the enclosure means including a transparent portion through which the first indicator may be viewed.

2. The clock assembly of claim 1, which includes a sec- I end rotatable sleeve surrounding the rotatable member and first sleeve, and a third indicator mounted on the second sleeve.

3. The clock assembly of claim 2, in which the first sleeve projects beyond the second sleeve, the rotatable member projects beyond the first sleeve, the second indicator and enclosure means are mounted on the projecting portion of the first sleeve, and the first indicator is mounted on the projecting portion of the rotatable memher.

4. The clock assembly of claim 1, in which the enclosure means includes a back wall portion having an opening therein for receiving and frictionally gripping the sleeve.

5. The clock assembly of claim 1, in which the second indicator is formed in part by the enclosure means.

References Cited in the file of this patent UNITED STATES PATENTS 1,934,387 Tweedale Nov. 7, 1933 2,188,872 Carlson Jan. 30, 1940 2,324,560 Conlon July 20, 1943 

